Let's look at the possibility that it was a deliberate action. I learned more that half a century ago that the wages of pilots were so very high because pilots shouldn't be worried about any thing but executing their work. Nowadays companies like German Wings safe money by paying much less than old fashioned companies like its mother Lufthansa. I read about a pilots living on the US East coast who flew on the West coast ( from LA IIRC ) for five days a week and then returned home for the weekend. While in LA he slept in a porta cabin beside an active runway because he couldn't pay for proper accommodation. There have been earlier allegation about pilots committing suicide by crashing aircraft with passengers, mostly disproved by the way, but there IIRC still suspicions about the Silk Air Boeing that crashed in a Sumatran river from a height of 10 km a few years ago.
A solution might be to re-establish proper norms for pilot pay and conditions. In general central banks are executing bizarre policies in order to achieve inflation while the old method is to increase wages. I remember that in 1963 angry collective wage negotiations in The Netherlands concerned wage increases would be 2.6% or 2.8% when the government decided the proper rate was 10% .....
Btw this is discussion in a thread that should contain any. Can this be moved to a separate thread?
Back in the good old days, it would be rare to become a Commercial Airline Pilot, unless you had served quite a few years flying "Heavies" for the Air Force. It is true that the rise of Budget Aitlines flying highly automated Short Hall Airliners, has reduced the skill threshold quite considerably, although I believe you still need a lot of time and experience before they let anyone take control of a real Long Haul Jumbo.
The budget airlines, like to take on youngsters as apprentices and take about 2 years to train them up. It is true that when they become fully fledged, that they are expected to work long hours and get paid considerably less than the rates formally associated with the occupation.
The Airlines argue that these guys are paid to learn how to fly and that once they have paid off the investment to the Airline and gain considerable experience, that they will have a very valuable professional skill for life.
In that sense these young pilots are not dissimilar to Junior Doctors in the UK's NHS (no idea how it works in your country) with lots of work, responsibility and stress, long hours and relatively low pay, but the future prospect of earning untold riches in Gen Practice or as a Consultant.
The key word is relative for while the Budget airlines pay their newly qualifieds much less than the top Big Airline Pilots, it is still a much higher than average income than the vast majority of their age group.
The latest claim today is evidence that he was feeling a bit down. Well we all feel a bit down from time to time, especially after a busy time. The answer is to take a break and go somewhere for a rest. It does not equate with feeling suicidal or spur of the moment suicide/mass homicide.
I do find it galling that we everybody is content to plump for the most sensational and damning option before the enquiry has even begun. He has already been found guilty in trial by media and this is unlikely to be corrected, even if the evidence fails to support the claims.
So while it is clear that he was the only person in the Cockpit, there is so far nothing that proves that he was actually in control of the plane or in control of events.
I am also minded that this would not be the first time, that authority have been happy to scapegoat dead pilots in order to cover up other far more serious failings of their own.